linux 用dd刻录速度慢,在mac中加快dd命令的运行速度

在用dd命令，将一个SD卡复制到另一个SD过程中，发现速度非常慢。

sudo diskutil unmount /dev/disk2s1

sudo diskutil unmount /dev/disk3s1

sudo dd bs=1m if=/dev/disk2 of=/dev/disk3

然后在另一个shell中运行命令可以查看进度情况：

sudo pkill -INFO dd # mac系统

sudo killall -USR1 dd # linux系统

3+0 records in

2+0 records out

20971520 bytes transferred in 39.393646 secs (532358 bytes/sec)

还有另外几种查看进度的方法：

CTRL + T

Sends SIGINFO to the process. This is a BSD feature OS X inherited. You must have the terminal window executing dd selected when entering CTRL + T for this to work.

pv -tpreb /dev/sda | dd of=/dev/sdb bs=1M

Your platform may not have pv by default. If you are using Homebew on OSX, simply ‘brew install pv’.

while pgrep ^dd; do pkill -INFO dd; sleep 10; done

While a dd is running in one terminal, open ano